Add new DeferredRegistry helper, and change RegistryObject to update when overrides are registered.

src/main/java/net/minecraftforge/client/event/ClientPlayerNetworkEvent.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2019.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
 package net.minecraftforge.client.event;
 
 import net.minecraft.client.entity.player.ClientPlayerEntity;

src/main/java/net/minecraftforge/client/event/ParticleFactoryRegisterEvent.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2019.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
 package net.minecraftforge.client.event;
 
 import net.minecraftforge.eventbus.api.Event;

src/main/java/net/minecraftforge/common/ForgeMod.java

@@ -29,10 +29,7 @@ import net.minecraftforge.fml.event.server.FMLServerStartingEvent;
 import net.minecraftforge.fml.event.server.FMLServerStoppingEvent;
 import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
 import net.minecraftforge.server.command.ConfigCommand;
-import net.minecraftforge.server.command.EnumArgument;
-import net.minecraftforge.server.command.ForgeArguments;
 import net.minecraftforge.server.command.ForgeCommand;
-import net.minecraftforge.server.command.ModIdArgument;
 import net.minecraftforge.versions.forge.ForgeVersion;
 import net.minecraftforge.versions.mcp.MCPVersion;
 
@@ -40,8 +37,6 @@ import org.apache.commons.lang3.tuple.Pair;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
-import net.minecraft.command.arguments.ArgumentSerializer;
-import net.minecraft.command.arguments.ArgumentTypes;
 import net.minecraft.data.DataGenerator;
 import net.minecraft.item.crafting.IRecipe;
 import net.minecraft.item.crafting.IRecipeSerializer;
@@ -68,7 +63,6 @@ import net.minecraftforge.common.data.ForgeRecipeProvider;
 import net.minecraftforge.common.model.animation.CapabilityAnimation;
 import net.minecraftforge.energy.CapabilityEnergy;
 import net.minecraftforge.event.RegistryEvent;
-import net.minecraftforge.event.entity.player.PlayerEvent;
 import net.minecraftforge.fml.event.lifecycle.GatherDataEvent;
 import net.minecraftforge.fluids.capability.CapabilityFluidHandler;
 import net.minecraftforge.items.CapabilityItemHandler;
@@ -134,7 +128,13 @@ public class ForgeMod implements WorldPersistenceHooks.WorldPersistenceHook
             VersionChecker.startVersionCheck();
         }
 
-        ForgeArguments.register();
+        /*
+         * We can't actually add any of these, because vanilla clients will choke on unknown argument types
+         * So our custom arguments will not validate client-side, but they do still work
+        ArgumentTypes.register("forge:enum", EnumArgument.class, new EnumArgument.Serializer());
+        ArgumentTypes.register("forge:modid", ModIdArgument.class, new ArgumentSerializer<>(ModIdArgument::modIdArgument));
+        ArgumentTypes.register("forge:structure_type", StructureArgument.class, new ArgumentSerializer<>(StructureArgument::structure));
+        */
     }
 
     public void serverStarting(FMLServerStartingEvent evt)

src/main/java/net/minecraftforge/fml/RegistryObject.java

@@ -21,7 +21,8 @@ package net.minecraftforge.fml;
 
 import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.registries.IForgeRegistry;
-import net.minecraftforge.registries.ForgeRegistryEntry;
+import net.minecraftforge.registries.IForgeRegistryEntry;
+import net.minecraftforge.registries.ObjectHolderRegistry;
 import net.minecraftforge.registries.RegistryManager;
 
 import java.util.Objects;
@@ -32,69 +33,76 @@ import java.util.function.Predicate;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
 
-public final class RegistryObject<T extends ForgeRegistryEntry<? super T>>
+import javax.annotation.Nullable;
-{
-    private final String name;
-    private final IForgeRegistry<?> owningRegistry;
-    private T value;
-    private boolean searched;
 
-    public static <T extends ForgeRegistryEntry<T>, U extends T> RegistryObject<U> of(final String name, Supplier<Class<? super T>> registryType) {
+public final class RegistryObject<T extends IForgeRegistryEntry<? super T>>
+{
+    private final ResourceLocation name;
+    @Nullable
+    private T value;
+
+    public static <T extends IForgeRegistryEntry<T>, U extends T> RegistryObject<U> of(final String name, Supplier<Class<? super T>> registryType) {
         return new RegistryObject<>(name, registryType);
     }
 
+    public static <T extends IForgeRegistryEntry<T>, U extends T> RegistryObject<U> of(final String name, IForgeRegistry<T> registry) {
+        return new RegistryObject<>(name, registry);
+    }
+
     private static RegistryObject<?> EMPTY = new RegistryObject<>();
 
-    private static <T extends ForgeRegistryEntry<? super T>> RegistryObject<T> empty() {
+    private static <T extends IForgeRegistryEntry<? super T>> RegistryObject<T> empty() {
         @SuppressWarnings("unchecked")
         RegistryObject<T> t = (RegistryObject<T>) EMPTY;
         return t;
     }
 
     private RegistryObject() {
-        this.searched = true;
+        this.name = null;
-        this.name = "";
-        this.owningRegistry = null;
     }
 
-    private <V extends ForgeRegistryEntry<V>> RegistryObject(String name, Supplier<Class<? super V>> registryType)
+    private <V extends IForgeRegistryEntry<V>> RegistryObject(String name, Supplier<Class<? super V>> registryType)
     {
-        this.name = name;
+        this(name, RegistryManager.ACTIVE.<V>getRegistry(registryType.get()));
-        IForgeRegistry<V> registry;
-        try {
-            registry = RegistryManager.ACTIVE.<V>getRegistry(registryType.get());
-        } catch (Throwable t) {
-            registry = null;
-        }
-        this.owningRegistry = registry;
     }
 
-    private T getValue()
+    @SuppressWarnings("unchecked")
+    private <V extends IForgeRegistryEntry<V>> RegistryObject(String name, IForgeRegistry<V> registry)
+    {
+        if (registry == null)
+            throw new IllegalArgumentException("Invalid registry argument, must not be null");
+        this.name = new ResourceLocation(name);
+        ObjectHolderRegistry.addHandler(pred ->
+        {
+            if (pred.test(registry.getRegistryName()))
+                this.value = registry.containsKey(this.name) ? (T)registry.getValue(this.name) : null;
+        });
+    }
+
+    /**
+     * Directly retrieves the wrapped Registry Object. This value will automatically be updated when the backing registry is updated.
+     */
+    @Nullable
+    public T get()
     {
-        if (!searched) {
-            if (this.owningRegistry != null) {
-                //noinspection unchecked
-                this.value = (T)this.owningRegistry.getValue(new ResourceLocation(this.name));
-            }
-            searched = true;
-        }
         return this.value;
     }
 
     public String getName() {
-        return this.name;
+        return this.name.toString();
     }
 
     public Stream<T> stream() {
-        return isPresent() ? Stream.of(getValue()) : Stream.of();
+        return isPresent() ? Stream.of(get()) : Stream.of();
     }
+
     /**
      * Return {@code true} if there is a mod object present, otherwise {@code false}.
      *
      * @return {@code true} if there is a mod object present, otherwise {@code false}
      */
     public boolean isPresent() {
-        return getValue() != null;
+        return get() != null;
     }
 
     /**
@@ -106,8 +114,8 @@ public final class RegistryObject<T extends ForgeRegistryEntry<? super T>>
      * null
      */
     public void ifPresent(Consumer<? super T> consumer) {
-        if (getValue() != null)
+        if (get() != null)
-            consumer.accept(getValue());
+            consumer.accept(get());
     }
 
     /**
@@ -126,7 +134,7 @@ public final class RegistryObject<T extends ForgeRegistryEntry<? super T>>
         if (!isPresent())
             return this;
         else
-            return predicate.test(getValue()) ? this : empty();
+            return predicate.test(get()) ? this : empty();
     }
 
     /**
@@ -149,7 +157,7 @@ public final class RegistryObject<T extends ForgeRegistryEntry<? super T>>
         if (!isPresent())
             return Optional.empty();
         else {
-            return Optional.ofNullable(mapper.apply(getValue()));
+            return Optional.ofNullable(mapper.apply(get()));
         }
     }
 
@@ -175,7 +183,7 @@ public final class RegistryObject<T extends ForgeRegistryEntry<? super T>>
         if (!isPresent())
             return Optional.empty();
         else {
-            return Objects.requireNonNull(mapper.apply(getValue()));
+            return Objects.requireNonNull(mapper.apply(get()));
         }
     }
 
@@ -187,7 +195,7 @@ public final class RegistryObject<T extends ForgeRegistryEntry<? super T>>
      * @return the mod object, if present, otherwise {@code other}
      */
     public T orElse(T other) {
-        return getValue() != null ? getValue() : other;
+        return get() != null ? get() : other;
     }
 
     /**
@@ -201,7 +209,7 @@ public final class RegistryObject<T extends ForgeRegistryEntry<? super T>>
      * null
      */
     public T orElseGet(Supplier<? extends T> other) {
-        return getValue() != null ? getValue() : other.get();
+        return get() != null ? get() : other.get();
     }
 
     /**
@@ -221,8 +229,8 @@ public final class RegistryObject<T extends ForgeRegistryEntry<? super T>>
      * {@code exceptionSupplier} is null
      */
     public <X extends Throwable> T orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
-        if (getValue() != null) {
+        if (get() != null) {
-            return getValue();
+            return get();
         } else {
             throw exceptionSupplier.get();
         }
@@ -233,7 +241,7 @@ public final class RegistryObject<T extends ForgeRegistryEntry<? super T>>
     {
         if (this == obj) return true;
         if (obj instanceof RegistryObject) {
-            return Objects.equals(((RegistryObject)obj).name, name);
+            return Objects.equals(((RegistryObject<?>)obj).name, name);
         }
         return false;
     }

src/main/java/net/minecraftforge/fml/network/FMLMCRegisterPacketHandler.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2019.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
 package net.minecraftforge.fml.network;
 
 import io.netty.buffer.Unpooled;

src/main/java/net/minecraftforge/registries/DeferredRegister.java

@@ -0,0 +1,98 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2019.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.registries;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Supplier;
+
+import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.event.RegistryEvent;
+import net.minecraftforge.eventbus.api.IEventBus;
+import net.minecraftforge.fml.RegistryObject;
+
+/**
+ * Utility class to help with managing registry entries.
+ * Maintains a list of all suppliers for entries and registers them during the proper Register event.
+ * Suppliers should return NEW instances every time.
+ *
+ *Example Usage:
+ *<pre>
+ *   private static final DeferredRegister<Item> ITEMS = new DeferredRegister<>(ForgeRegistries.ITEMS, MODID);
+ *   private static final DeferredRegister<Block> BLOCKS = new DeferredRegister<>(ForgeRegistries.BLOCKS, MODID);
+ *
+ *   public static final RegistryObject<Block> ROCK_BLOCK = BLOCKS.register("rock", () -> new Block(Block.Properties.create(Material.ROCK)));
+ *   public static final RegistryObject<Item> ROCK_ITEM = ITEMS.register("rock", () -> new BlockItem(ROCK_BLOCK.get(), new Item.Properties().group(ItemGroup.MISC)));
+ *
+ *   public ExampleMod() {
+ *       ITEMS.register(FMLJavaModLoadingContext.get().getModEventBus());
+ *       BLOCKS.register(FMLJavaModLoadingContext.get().getModEventBus());
+ *   }
+ *</pre>
+ *
+ * @param <T> The base registry type, must be a concrete base class, do not use subclasses or wild cards.
+ */
+public class DeferredRegister<T extends IForgeRegistryEntry<T>>
+{
+    private final IForgeRegistry<T> type;
+    private final String modid;
+    private List<Supplier<? extends T>> entries = new ArrayList<>();
+
+    public DeferredRegister(IForgeRegistry<T> reg, String modid)
+    {
+        this.type = reg;
+        this.modid = modid;
+    }
+
+    /**
+     * Adds a new supplier to the list of entries to be registered, and returns a RegistryObject that will be populated with the created entry automatically.
+     *
+     * @param name The new entry's name, it will automatically have the modid prefixed.
+     * @param sup A factory for the new entry, it should return a new instance every time it is called.
+     * @return A RegistryObject that will be updated with when the entries in the registry change.
+     */
+    public <I extends T> RegistryObject<I> register(final String name, final Supplier<I> sup)
+    {
+        final ResourceLocation key = new ResourceLocation(modid, name);
+        entries.add(() -> sup.get().setRegistryName(key));
+        return RegistryObject.of(key.toString(), this.type);
+    }
+
+    /**
+     * Adds our event handler to the specified event bus, this MUST be called in order for this class to function.
+     * See the example usage.
+     *
+     * @param bus The Mod Specific event bus.
+     */
+    public void register(IEventBus bus)
+    {
+        bus.addListener(this::addEntries);
+    }
+
+    private void addEntries(RegistryEvent.Register<?> event)
+    {
+        if (event.getGenericType() == this.type.getRegistrySuperType())
+        {
+            @SuppressWarnings("unchecked")
+            IForgeRegistry<T> reg = (IForgeRegistry<T>)event.getRegistry();
+            entries.stream().map(Supplier::get).forEach(reg::register);
+        }
+    }
+}

src/main/java/net/minecraftforge/registries/RegistryManager.java

@@ -19,7 +19,6 @@
 
 package net.minecraftforge.registries;
 
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;

src/main/java/net/minecraftforge/server/command/ForgeArguments.java

@@ -1,15 +0,0 @@
-package net.minecraftforge.server.command;
-
-public class ForgeArguments
-{
-    public static void register()
-    {
-        /*
-         * We can't actually add any of these, because vanilla clients will choke on unknown argument types
-         * So our custom arguments will not validate client-side, but they do still work
-        ArgumentTypes.register("forge:enum", EnumArgument.class, new EnumArgument.Serializer());
-        ArgumentTypes.register("forge:modid", ModIdArgument.class, new ArgumentSerializer<>(ModIdArgument::modIdArgument));
-        ArgumentTypes.register("forge:structure_type", StructureArgument.class, new ArgumentSerializer<>(StructureArgument::structure));
-        */
-    }
-}